U.S. Pat. Nos. 4,711,975 and 4,492,812 each disclose cable splice closures in which casing half-shells are fastened together by means of interlocking protrusions and apertures arranged along opposing edges of the half-shells. Cable splice closures as disclosed in these two patents suffer from the disadvantage that they are generally difficult to open and close.
According to the present invention, there is provided a cable splice closure, comprising first and second casing parts, opposing edges of which may be brought together to close the closure, a series of protrusions extending along the exterior of the first casing part adjacent to a said edge, and a series of openings extending adjacent to a said edge of the second casing part in an extending wall which, when the closure is closed, overlaps the exterior of the first casing part such that each protrusion is resiliently interlocked with a respective opening, characterised in that the second casing part includes a plurality of apertures in its extending wall for receiving a lever to force the casing parts together such that the respective protrusions and openings interlock and/or to force the casing parts apart such that the respective protrusions and openings disengage.
The cable splice closure according to the invention has the advantage that it is normally easier to open and close than the known closures, because the second casing part includes apertures in its extending wall which permit the use of a lever (e.g. a screwdriver or the like) to force the casing parts together and/or apart. The known closures do not have this advantage, so they must normally be opened and closed by hand, without the use of tools.
In preferred embodiments of the invention, each aperture extends completely through the extending wall from an exterior surface to an interior surface of the wall, thereby permitting a lever to be inserted through the aperture from the exterior surface of the wall and into engagement with the exterior of the first casing part, in order to force the casing parts together. Preferably, the exterior of the first casing part includes at least one shoulder arranged to be engaged by a lever received in an aperture when the casing parts are being forced together.
Additionally or alternatively, each aperture preferably comprises a recess in an interior surface of the extending wall which is open to a front edge of the wall, thereby permitting a said lever to be inserted between the extending wall and the exterior of the first casing part, in order to disengage respective said protrusions and openings when they are interlocked in use.
Preferably the apertures in the extending wall are arranged in a series along the wall. Advantageously each aperture may be associated with a respective opening, or a respective pair of openings, for example. Each aperture is preferably situated between at least one respective opening in the extending wall and the front edge of the wall. Additionally or alternatively, each aperture may be situated between a respective pair of openings in the extending wall.
The first and second casing parts preferably comprise half-shells. In some preferred embodiments, the first and second casing parts are completely separable from one another, e.g. having two pairs of opposing edges which are substantially parallel to the direction in which cables extend into the closure in use. In other embodiments, the first and second casing parts are hinged together, e.g. having only one pair of opposing edges, which are substantially parallel to the direction of the cables. The casing parts are preferably formed from a polymer, e.g. polyethylene or polypropylene.
Each pair of opposing edges is preferably sealed, in use, by means of at least one sealing member. The or each sealing member is preferably resilient, e.g. having a low compression set. The compression set of the material of the sealing member(s) is preferably no greater than 40%, more preferably no greater than 30%, as measured according to ISO 815, i.e. 50% compression strain at 70.degree. C. for 22 hours, measured after a recovery time of 30 minutes.
The resilience and low compression set of the preferred sealing member(s) have the advantage that they contribute to the maintenance of a good seal over time. Additionally, they may also have the advantage of facilitating the opening of the closure, by pushing the two casing parts apart as the protrusions and openings are disengaged from each other.
The or each sealing member is preferably hollow, e.g. generally tubular and/or formed from a foam material. The material of the sealing member(s) is preferably polymeric, e.g. elastomeric. A particularly preferred material is natural or synthetic rubber, e.g. a silicone or EPDM rubber.